Highly reliable service port

Abstract

A port for use in introducing a fluid into an internal fluid chamber includes a plug bore, a valve disposed in the plug bore and a plug. The plug includes one or more seal grooves and a ring seal in each of the one or more seal grooves. The ring seal creates a seal between the plug and the plug bore. The port further includes a positive stop barrier that prevents the plug from being removed from the plug bore.

What is claimed is: 
     
       1. A port for use in transferring a fluid to and from an internal fluid chamber, the port comprising:
 a plug bore, wherein the plug bore comprises:
 a non-threaded upper bore; and 
 a lower bore with a threaded portion; 
 
 a plug configured for a non-threaded engagement with the plug bore to selectively close and seal the plug bore, wherein the plug comprises:
 a head configured to be accepted within the non-threaded upper bore, wherein the head includes one or more seal grooves; 
 a stem extending into the lower bore above the threaded portion, wherein the stem does not include a passage that permits the fluid to pass through the stem; and 
 one or more ring seals, wherein each of the one or more ring seals is captured in a corresponding one of the one or more seal grooves; and 
 
 a valve assembly captured by a threaded engagement within the threaded portion of the lower bore. 
 
     
     
       2. The port of  claim 1 , wherein the plug bore comprises:
 a service opening; and 
 a stop groove adjacent the service opening. 
 
     
     
       3. The port of  claim 2  further comprising a positive stop barrier retained within the stop groove. 
     
     
       4. The port of  claim 3 , wherein the positive stop barrier is a snap ring.